A hardware device that provides the basic infrastructure for a home or small office network. By combining three network components in one box, wireless routers offer a convenient way to connect a small number of wired and any number of wireless devices to each other for access to the Internet as well as for file sharing and printing. All in One: Access Point, Switch and Router The access point is the base station and antenna that transmits and receives Wi-Fi signals. The switch interconnects any number of Wi-Fi devices and from three to four wired devices via Ethernet cables. The router forwards and receives Internet traffic via the user's modem, which connects to a line from the cable or telephone company. See access point, Ethernet switch and router. Assign and Keep Track A major function of the router is to assign an IP address to the computers and devices in the network (see DHCP). Another important task is keeping track of all queries to the Internet in order to forward the response back to the device that made the request (see NAT). Also a Firewall The router attempts to prevent unrequested traffic from coming into the network. Most wireless routers contain a stateful inspection firewall that ensures packets (Web pages, e-mail, etc.) coming from the Internet were requested by a user. Because the router is the only path to the Internet, the firewall works for all computers in the network, and personal firewalls in each machine may be turned off (see firewall and firewall methods). See modem vs. router, wireless LAN, Wi-Fi, Wi-Fi hotspot, cellular hotspot, Wi-Fi extender, Ethernet switch, router and WPAN.